Coordination is the conscious activity of assembling and synchronizing differentiated work efforts so that they function harmoniously in attainment of organizational objectives. Coordination of patient care is considered an important element of the quality of care delivered; several studies suggest that a higher degree of coordination is associated with better patient outcomes. However, past attempts to describe the mechanisms of coordination have been done in highly centralized and contained inpatient units such as intensive care and surgical units. What constitutes good coordination in the outpatient setting and how it affects patient health outcomes is largely unknown. As an increasing proportion of health care moves to the outpatient setting, there is a need to identify the specific mechanisms of coordination that successfully bridge the gaps in the decentralized and often fragmented system of outpatient care and will result in improved health outcomes and patient satisfaction. Certain medical conditions such as those requiring specialized diagnostics and treatments provided by different disciplines in a particular sequence in a limited time frame may be sensitive to the effects of coordination of care. We propose to assess the coordination of care for women diagnosed with early-stage breast cancer, a relatively common disease which requires the care of numerous different specialists in a sequential fashion, for which treatments can improve health outcomes. In the proposed study, we will use a case study methodology to investigate how six hospitals coordinate early-stage breast cancer care. We will identify and describe specific coordination mechanisms that potentially play a role facilitating the coordination of care delivered in the outpatient setting generally and for early-stage breast cancer specifically; we will refine the study's conceptual framework and advance theoretical propositions that can be tested systematically through large-scale studies.